U.S. Pat. No. 7,728,074 to Kluttz et al. and assigned to Kraton Polymers LLC discloses a block copolymer for uniformly mixing with a bitumen binder for hot mix asphalt paving applications. The block copolymer is a mixture of a diblock and triblock styrenic block copolymer where the diblock to triblock ratio is greater than 1:1. This patent is hereby incorporated by reference.
It is known to use 20 to 30 wt. % of reclaimed asphalt in prior art compositions. These compositions rejuvenate the RAP (reclaimed asphalt pavement) with oil. U.S. Pat. No. 8,133,316 to Poncelet et al. and assigned to Shell oil Company describes a process for mixing RAP with virgin asphalt composition. The heated RAP is mixed with mineral or vegetable oil such as rape seed or palm oil, or an animal oil, up to 10 wt. %. Thereafter it is mixed with the virgin asphalt composition (asphalt and gravel/sand). No bio-based oil, nor styrenic block copolymer is disclosed.
U.S. Pat. No. 7,560,503 to St. Clair et al. and assigned to Kraton Polymers LLC discloses a gel made from a blend of 1 part styrenic block copolymer and 3 to 20 parts oil. The styrenic block copolymer can be a combination of a high vinyl diblock and a high vinyl triblock copolymer.
U.S. Pat. No. 9,115,296 to Kluttz et al. and assigned to Kraton Polymers LLC relates to bituminous emulsions. The styrenic block copolymer is a mixture of a diblock and triblock styrenic block copolymer where the diblock to triblock ratio is greater than 1:1. This patent is hereby incorporated by reference.
The use of SBS (styrene-butadiene-styrene) in fresh asphalt blends is known to improve permanent deformation at high temperatures, improve crack resistance at intermediate and low temperatures, and improve age resistance through brittleness. Nevertheless, the industry continually seeks asphalt payment that employs recycled asphalt with polymer and oil that results in a long lasting pavement.